Okhttp 3：如何使用Java/Android手动解压缩gzip/deflate响应

wko9yo5t 于 2022-10-09 发布在 Java

关注(0)|答案(3)|浏览(262)

我知道okhttp3库默认情况下会添加标题Accept-Encoding: gzip，并自动为我们解码响应。

我正在处理的问题是，主机只接受像Accept-Encoding: gzip, deflate这样的头，如果我不添加deflate部分，它就会失败。现在，当我手动将头文件添加到okhttp客户端时，库不再为我执行解压缩。

我尝试了多种解决方案来获取响应，并尝试手动解压缩，但我总是得到一个异常，即java.util.zip.ZipException: Not in GZIP format，以下是我到目前为止尝试的方法：

//decompresser
public static String decompressGZIP(InputStream inputStream) throws IOException
{
    InputStream bodyStream = new GZIPInputStream(inputStream);
    ByteArrayOutputStream outStream = new ByteArrayOutputStream();
    byte[] buffer = new byte[4096];
    int length;
    while ((length = bodyStream.read(buffer)) > 0) 
    {
        outStream.write(buffer, 0, length);
    }

    return new String(outStream.toByteArray());
}

//run scraper
scrape(api, new Callback()
{
    // Something went wrong
    @Override
    public void onFailure(@NonNull Call call, @NonNull IOException e)
    {
    }

    @Override
    public void onResponse(@NonNull Call call, @NonNull Response response) throws IOException
    {
        if (response.isSuccessful())
        {
            try
            {
                InputStream responseBodyBytes = responseBody.byteStream();
                returnedObject = GZIPCompression.decompress(responseBodyBytes);

                if (returnedObject != null)
                {
                    String htmlResponse = returnedObject.toString();
                }
            }
            catch (ProtocolException e){}

            if(response != null) response.close();
        }
    }
});

private Call scrape(Map<?, ?> api, Callback callback)
{
    MediaType JSON = MediaType.parse("application/json; charset=utf-8");
    String method = (String) api.get("method");
    String url = (String) api.get("url");
    Request.Builder requestBuilder = new Request.Builder().url(url);
    RequestBody requestBody;

    requestBuilder.header("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0");
    requestBuilder.header("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
    requestBuilder.header("Accept-Language", "en-US,en;q=0.5");
    requestBuilder.header("Accept-Encoding", "gzip, deflate");
    requestBuilder.header("Connection", "keep-alive");
    requestBuilder.header("Upgrade-Insecure-Requests", "1");
    requestBuilder.header("Cache-Control", "max-age=0");

    Request request = requestBuilder.build();

    Call call = client.newCall(request);
    call.enqueue(callback);

    return call;
}

请注意，响应标头将始终返回Content-Encoding: gzip和Transfer-Encoding: chunked

还有一件事，我也尝试了this topic中的解决方案，但在D/OkHttp: java.io.IOException: ID1ID2: actual 0x00003c68 != expected 0x00001f8b中仍然失败。

如有任何帮助，我们将不胜感激。

android

来源：https://stackoverflow.com/questions/51901333/okhttp-3-how-to-decompress-gzip-deflate-response-manually-using-java-android

3条答案

按热度按时间

qco9c6ql1#

经过6个小时的挖掘，我找到了正确的解决方案，像往常一样，它比我想象的要容易，所以我基本上是在试着解压缩一个没有压缩的页面，因为这个原因它失败了。现在，一旦我访问第二个页面(它是压缩的)，我就会得到一个gzip响应，上面的代码应该可以处理它。此外，如果任何人想要解决方案，我使用了一个修改过的拦截器，就像this answer中的那样，所以您不需要使用自定义函数来处理解压缩。

我修改了unzip方法，使okhttp e1d1e可以处理压缩和未压缩的响应：

OkHttpClient.Builder clientBuilder = new OkHttpClient.Builder().addInterceptor(new UnzippingInterceptor());
OkHttpClient client = clientBuilder.build();

而拦截器就像是dis：

private class UnzippingInterceptor implements Interceptor {
    @Override
    public Response intercept(Chain chain) throws IOException {
        Response response = chain.proceed(chain.request());
        return unzip(response);
    }

// copied from okhttp3.internal.http.HttpEngine (because is private)
private Response unzip(final Response response) throws IOException {
    if (response.body() == null)
    {
        return response;
    }

    //check if we have gzip response
    String contentEncoding = response.headers().get("Content-Encoding");

    //this is used to decompress gzipped responses
    if (contentEncoding != null && contentEncoding.equals("gzip"))
    {
        Long contentLength = response.body().contentLength();
        GzipSource responseBody = new GzipSource(response.body().source());
        Headers strippedHeaders = response.headers().newBuilder().build();
        return response.newBuilder().headers(strippedHeaders)
                .body(new RealResponseBody(response.body().contentType().toString(), contentLength, Okio.buffer(responseBody)))
                .build();
    }
    else
    {
        return response;
    }
}
}

赞(0）回复(0）举报 2022-10-09

camsedfj2#

如果您的标题包含gzip，则版本4.10.0已经可以自动执行此操作

赞(0）回复(0）举报 2022-10-09

y53ybaqx3#

因为okhttp不支持放气

在BridgeInterceptor.java或BridgeInterceptor.kt中

if (transparentGzip &&
    "gzip".equals(networkResponse.header("Content-Encoding"), ignoreCase = true) &&
    networkResponse.promisesBody()) {

赞(0）回复(0）举报 2022-10-09

我来回答

Okhttp 3：如何使用Java/Android手动解压缩gzip/deflate响应

3条答案

相关问题

热门标签

最新问答